Timing?
High octane fuel, in general, does not REQUIRE more timing. It might tolerate more, but it should not need more. There are a lot of people who mistakenly think that high octane fuel burns more slowly, and that has been spread around on the internet, even though it is not correct. Here is a quote, originally from Popular Hot Rodding:
"The burn rate of a fuel is a measurement of the time required
for complete combustion of the air/fuel mixture. The notion that octane ratings affect the burn rate of fuel is about 180-degrees from reality;
bum rate is a function of several variables, and the two are completely independent, although there is generally a correlation between octane ratings and bum rates.
To give you a good example of this, we contacted Jim Wurth from
Sunoco Race Fuels. He explains, "A perfect example is Sunoco Maximal,which is our fastest burning fuel, and coincidentally one of Sunoco'shighest octane fuels at 116 (R+M) / 2. A lot of Pro Stock teams rely on Maximal for those sub-seven second runs. When they are turning 9,000 rpm or more, the fuel has to burn pretty quickly to achieve complete combustion."
So, maybe try a little less timing, see how it works.